If you’ve driven east from Canyon County toward Boise recently, you’ve probably seen the big white “Knife River” tube running across Interstate 84 between the median and the right shoulder.

It is a behemoth, just 17 feet off the ground. Spanning 124 feet with a mouth six feet in diameter, the tube serves as a massive conveyor, delivering materials to the work area for the Meridian to Garrity widening project under way. The tube is expected to be in place through mid-August, although the widening project will continue until 2010.

When complete, the reconstructed interstate below the tube will have three lanes and a median barrier between Nampa and Meridian. Combined, interstate will have six lanes in the area. The I-84, Garrity to Meridian project is expected to cost approximately $113 million.

The primary purpose of the conveyor is a safety issue - to eliminate the clashes that might occur between trucks bringing in job materials and the traveling public.

The conveyor tube will be used to safely transport construction material into the median during the widening project without disrupting traffic.

A similar conveyor method has been used a few times before in southwest Idaho, on the Wye Interchange and Cole/Overland Interchange projects.